An estrogen binding protein has been isolated from Candida albicans, a normal yeast member of human microbiological flora that causes opportunistic infections in immunocompromised individuals and in otherwise healthy women. Evidence has been presented that estrogens can stimulate conversion of the normal yeast form of Candida to the infectious hyphal form suggesting that levels of circulating estrogens may directly affect the virulence of resident Candida. The estrogen binding protein from Candida has been cloned and sequenced and found to be ca. 45% identical to a flavoprotein from Saccharomyces cerevisiae known as old yellow enzyme. Although the function of OYE is not yet known, the crystal structure has recently been determined. We have begun studies to characterize the EBP from Candida and compare its ligand binding and catalytic properties with those of OYE in an initial effort to determine what its in vivo function is and how this may relate to the morphological changes and infectious properties of the yeast. Our current use of the Graphics Lab in relation to this project primarily involves evaluation of the structural properties of old yellow enzyme as a homologous enzyme that can also bind some of the same steroid molecules, although the binding modes are not well characterized. We are also interested in looking for other proteins that may show homologous sequences in certain regions of the protein. We have not attempted homology modeling of the EBP enzyme yet, but will likely pursue that in the near future.